Recently, with the advancement of robot technology, technical fields using robots are diversified. In the fields, the demand for robots and self-driving vehicles which travels outdoors increases progressively. Particularly, in robots and self-driving vehicles, advanced countries such as the USA and Japan lead the advancement of technology associated with outdoor autonomous running through various events.
However, the reason that outdoor self-driving vehicles and robots are not widely used by general users is because the self-driving vehicles and the robots cannot actually show high-level performance the user desires.
Especially, it is very important to accurately measure locations of a self-driving vehicle and a robot which travels outdoors. However, even though expensive equipment such as RTK-DGPS, LIDAR, and INS are used, the performance of the equipment is restricted in some areas. Also, even though the location of a robot is accurately estimated using an expensive positioning sensor, the sensor is too expensive for general users to use.
For this reason, it is required to develop a method that accurately estimates the location of a moving object by using a low-cost sensor.